Before main quests i dont have that red coin bag anywheere, after quest i have coin bag and cant leave without paying. Example: “The Prey” Didnt comit any crimes befor i met Hans in morning (checked to make sure). Did quest saved him from Cumins, went to meet Sir Bernard in the courtyard and all of the sudden every guard was on me, even Sir Bernard. The fine was 300 couldnt do anything untill i paid. this was forth time this has happened after a main quest. Also they never say what you did just your gona pay or something to that affect.
Have you been in a blue or red zone? At night or at morning, and you did not wear a torch?